Competent functioning is a goal of adulthood which requires using social relationships, which are organized into social networks, to solve life problems. Four studies are proposed, over a 3-year period, to explore adolescent social relationships. These studies explore social relationships using the concept of social networks. Size, structure, interaction content, and the problem solving function of networks. Size, structure, interaction content, and the problem solving function of networks will be examined. These dimensions will be related to adolescent psycho-social maturity. Two major untested hypotheses are posed: (a) social networks increase in complexity with age; (b) availability of complex and functional networks is related to advanced psycho-social maturity. Secondary hypotheses are: (c) social networks of males will be more complex and functional than those of females: (d) quality of social networks will be more likely to predict psycho-social maturity for females than for males. Participants will be 650 black, upper- to lower-middle SES adolescents, aged 13-15 and 18-21 of both sexes from the Baltimore-Washington area. A cross-sectional design will be used. Study I (n+100) explores the size and structure of social networks using a schematic questionnaire. Study II (n=250) validates the results of Study I. Study III (n=150, subset of II) uses a phone adminstered problem solving interview to explore functions of social networks. In Study IV (n=300) dimensions of networks are considered as predictors of psycho-social maturity. Aspects of maturity will include: independence (Assertiveness Scale); perceptions of ability, personality and status (Self-concept Scale); work orientation (Interpersonal Style Scale); and interpersonal communication style (simulated laboratory situation). Simple and canonical correlation and multiple regression analyses will be used to examine relationships among social network variables and between network and maturity variables. Results may help explain the social tasks adolescents must complete to achieve the status of healthy functioning adulthood. Results may also be applicable to understanding social support antecedents of adolescent pregnancy and other risk-taking behaviors.